JP2011069293A - Vacuum pump system and method for operating the same - Google Patents

Abstract

The present invention eliminates overload without increasing the required power capacity of a vacuum pump system as a whole even when the dry vacuum pump due to biting or the like becomes overloaded and the power capacity supplied to the driving motor increases. An object of the present invention is to provide a vacuum pump system that can be operated and a method of operating the same.
SOLUTION: A plurality of dry vacuum pumps are provided, electric power for driving each pump is supplied from inverter devices INV _MP and INV _BP , and when an overload is applied to the pump rotor, the inverter device is driven to the motor. In a vacuum pump system capable of supplying a maximum current up to several times the rated current, when the main pump MP or the booster pump BP is overloaded, the power supplied to the power consumption unit is cut off, and The power supplied to the motor of the vacuum pump that is not overloaded is limited, and the power is preferentially supplied to the motor of the vacuum pump that is overloaded.
[Selection] Figure 1

Description

  The present invention relates to a vacuum pump system including a plurality of two-axis positive displacement dry vacuum pumps and an operation method thereof.

  In recent years, dry vacuum pumps that can operate from atmospheric pressure and can easily obtain a clean vacuum environment have been used in a wide range of fields such as semiconductor manufacturing facilities. This type of dry vacuum pump includes two pump rotors in a rotor casing, and each pump rotor is a positive displacement dry vacuum pump having a single rotating shaft.

  In many cases, a power supply device that includes an inverter device is used as a power supply device that supplies driving power to the drive motor that drives the dry vacuum pump as described above. There are several reasons for this, and one of them is to increase the rotational speed of the motor by increasing the rotational speed of the motor by using an inverter device higher than the commercial frequency, thereby improving the exhaust performance of the vacuum pump. This is because a vacuum with a predetermined degree of vacuum is obtained with a vacuum pump using a small electric motor.

  Also, if the operation of the vacuum pump reaches the desired degree of vacuum and the load becomes a light load operation with a very low load, the output terminal voltage of the power supply device is controlled or the rotation speed so that the motor can be operated with high efficiency. This is because it is easy to control.

  As described above, in the power supply device equipped with the inverter device, the rated current is set in accordance with the capacity of the motor that supplies the drive power, and the output limit is limited to about 1.1 times the rated current in normal operation. Is going. On the other hand, in a power supply device for a dry vacuum pump provided with an inverter device used in a semiconductor manufacturing device or the like, a biting state is likely to occur due to a product generated inside the pump or a foreign matter flowing into a flow path. For this reason, there is a case in which control is used to eliminate the biting state while crushing foreign matter at the start-up by supplying a maximum current up to about several times the rated current from the inverter device to the drive motor.

  In addition, the vacuum pump installed in the semiconductor manufacturing equipment has an event that the flow rate of the handling gas exhausted by the pump suddenly changes and rapidly increases depending on the usage state of the equipment. There are cases where a current supply of about three times is required.

JP 2009-91919 A

  However, if the entire vacuum pump system is designed as electric power that always uses several times the required rated current exceeding the upper limit value of the output current set in the inverter of the power supply device equipped with the conventional inverter device, the vacuum pump system Since an excessive power capacity is required, there is a problem that the entire vacuum system is enlarged and the equipment capacity is also increased.

  The present invention has been made in view of the above points, and is necessary as a whole vacuum pump system even when the dry vacuum pump due to biting or the like is overloaded and the power capacity supplied from the inverter device to the driving motor becomes large. It is an object of the present invention to provide a vacuum pump system that can supply a large amount of electric power necessary to eliminate an overload to a drive motor that drives a vacuum pump without increasing a large power capacity, and an operation method thereof.

  In order to solve the above-described problems, the present invention includes a pair of pump rotors in a rotor casing, and a plurality of two-shaft displacement dry vacuum pumps each having one rotating shaft. At least one of the rotating shafts is rotationally driven by an electric motor. The electric motor is supplied with driving power from the inverter device, and when the pump rotor is overloaded, the electric motor is transferred from the inverter device to the electric motor. In a vacuum pump system equipped with a power consumption unit that consumes power in addition to multiple motors, the maximum current up to several times the rated current can be supplied. When any of the pump rotors is overloaded, the power supplied to the power consuming unit other than the motor is cut off or restricted, and / or a plurality of dry vacuum pumps are used. Limit the power supplied to the motor that drives the dry vacuum pump that is not overloaded to the pump rotor, and supply power to the motor that drives the dry vacuum pump that is overloaded to the pump rotor. Further, it is characterized in that power control means for returning to the original power supply state after the overload is eliminated is provided.

  Further, the present invention is the above-described vacuum pump system, wherein the power consuming unit other than the electric motor is individually provided in each dry vacuum pump, and is a heater for individually controlling the temperature of the dry vacuum pump. And

  In the vacuum pump system according to the present invention, the overload of the pump rotor is an overload due to a pair of pump rotors or a foreign matter biting into the pump rotor and the rotor casing or a sudden increase in gas flow rate.

  Further, in the vacuum pump system according to the present invention, the plurality of dry vacuum pumps are a main dry vacuum pump and a booster dry vacuum pump, and a suction port of the main dry vacuum pump is connected to a discharge port of the booster dry vacuum pump. It is characterized by.

  The present invention also includes a pair of pump rotors in the rotor casing, each including a plurality of two-shaft capacity type dry vacuum pumps each having one rotation shaft, and at least one of the rotation shafts of each dry vacuum pump is The motor is rotated by an electric motor. The electric motor is supplied with driving power from the inverter device, and when the pump rotor is overloaded, the inverter device to the electric motor has several times the rated current of the electric motor. In the operation method of the vacuum pump system that can supply the maximum current as the upper limit and further includes a power consumption unit that consumes power in addition to the plurality of motors, any one of the plurality of dry vacuum pumps When the pump rotor is overloaded, the power supplied to the power consuming unit other than the motor is cut off or limited, and / or the pumps in the plurality of dry vacuum pumps Limit the power supplied to the motor that drives the dry vacuum pump that is not overloaded to the protor, and supply power to the motor that drives the dry vacuum pump that is overloaded to the pump rotor. After the problem is solved, the original power supply state is restored.

  The present invention cuts off or restricts power supplied to a power consuming unit other than an electric motor and / or the plurality of dry vacuum pumps when any of the pump rotors in the plurality of dry vacuum pumps is overloaded. Limit the power supplied to the motor that drives the dry vacuum pump that is not overloaded to the pump rotor, and supply power to the motor that drives the dry vacuum pump that is overloaded to the pump rotor. Since the original power supply state is restored after the overload is eliminated, the power capacity required for the entire vacuum pump system including the inverter device that supplies the electric motor that drives the dry vacuum pump is not changed, The maximum current up to several times the rated current is supplied to the motor that drives the dry vacuum pump, which is overloaded due to foreign object biting or sudden increase in gas flow rate. It can be. This effectively eliminates the product in the dry vacuum pump without changing the power capacity of the vacuum pump system.

FIG. 1 is a diagram showing a system configuration example of a vacuum pump system according to the present invention. FIG. 2 is a diagram showing a schematic arrangement example of a plurality of vacuum pumps in the vacuum pump system according to the present invention. FIG. 3 is a diagram showing an internal configuration example of a vacuum pump used in the vacuum pump system according to the present invention. FIG. 4 is a diagram showing a change state of power consumption when biting occurs in a conventional vacuum pump system. FIG. 5 is a diagram showing a change state of power consumption when biting occurs in the vacuum pump system according to the present invention. FIG. 6 is a diagram showing a change state of power consumption when biting occurs in the vacuum pump system according to the present invention. FIG. 7 is a view showing a comparative example of the vacuum pump system according to the present invention and a conventional vacuum pump device.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a diagram showing a system configuration of a vacuum pump system according to the present invention. As shown in the drawing, the present vacuum pump system 10 includes a main pump (MP) 11 and a booster pump (BP) 12 which are a biaxial volume type dry vacuum pump, a main pump (MP) 11 and a booster pump ( As will be described later in detail, the BP) 12 connects the suction port (intake port) of the main pump 11 to the discharge port (exhaust port) of the booster pump 12.

As will be described later in detail, the main pump 11 and the booster pump 12 are a biaxial volumetric dry vacuum pump having a pair of pump rotors in a rotor casing and each having one rotating shaft, and at least one of the rotating shafts. One is driven to rotate by a drive motor. Reference numeral 14 denotes a main pump power supply device including an inverter device INV _MP, and reference numeral 15 denotes a booster pump power supply device including an inverter device INV _BP .

The main pump (MP) 11 and the booster pump (BP) 12 are respectively provided with a main pump heater (H _MP ) 20 and a booster pump heater (H _BP ) 21, and the main pump heater ( H _MP ) 20 and booster pump heater (H _BP ) 21 are controlled to be supplied with heating current (electric power) under the control of main pump heater controller 23 and booster pump heater controller 24, respectively. Yes. Reference numeral 35 denotes a main pump cooling water introduction pipe for introducing the cooling water 100 into the main pump 11 via the main pump flow control valve (V _MP ) 32, and 36 denotes a booster pump flow control valve (V _BP ) 33. This is a booster pump cooling water introduction pipe for introducing the cooling water into the booster pump 12. The cooling water introduced into the main pump 11 and the booster pump 12 through the main pump cooling water introduction pipe 35 and the booster pump cooling water introduction pipe 36 is a heat exchanger (not shown) provided in the main pump 11 and the booster pump 12. The heat is exchanged and drained through the drain pipe 37.

  Reference numeral 30 denotes a main control device, which includes a main pump power supply device 14, a booster pump power supply device 15, a main pump heater control device 23, a booster pump heater control device 24, and a main pump flow control. The valve 32 and the booster pump flow control valve 33 are controlled. Reference numeral 26 denotes a breaker, and through the breaker 26, from an AC power source (commercial power supply) 28, a main pump electromagnetic switch 17, a booster pump electromagnetic switch 18, a main pump heater control device 23, and a booster pump Electric power is supplied to the heater control device 24.

FIG. 2 is a diagram showing an arrangement configuration example of the main pump (MP) 11 and the booster pump (BP) 12 of the vacuum pump system 10 according to the present invention, and FIG. 2 (a) shows the main pump (MP) 11 and the booster pump ( FIG. 2 (b) shows a host device linked operation mode in which the main pump 11 (MP) and the booster pump (BP) 12 are linked to the host device. As shown in the figure, the vacuum pump system 10 has a booster pump (BP) 12 and a main pump (MP) 11 arranged vertically in a casing 41, and a discharge port (exhaust port) of the booster pump (BP) 12. 12 b is connected to a suction port (intake port) 11 a of the main pump (MP) 11. M _BP is a booster pump drive motor that drives the booster pump (BP) 12, and M _MP is a main pump drive motor that drives the main pump (MP) 11.

In the vacuum pump system 10, in the case of a single operation mode, as shown in FIG. 2A, the booster pump drive motor M _BP is operated under the control of the main controller 30 by operating the operation panel 43. The booster pump 12 is rotationally driven in response to driving power from the power supply device 15 for power. The main pump drive motor M _MP receives drive power from the main pump power supply device 14 under the control of the main control device 30 and rotationally drives the main pump (MP) 11. Further, in the case of the host device cooperative operation mode, as shown in FIG. 2B, the booster pump drive motor M _BP is controlled under the control of the main controller 30 via the host device and the interface (I / F). The main pump drive motor M _MP receives the drive power from the booster pump power supply 15 and the main pump power supply 14 and rotates the main pump (MP) 11 and the booster pump (BP) 12 in the same manner as described above. .

Next, FIG. 3 is a diagram illustrating a configuration example of the main pump 11. Since the booster pump 12 has the same configuration as the main pump 11, only the main pump 11 will be described here. The booster pump 12 and the main pump 11 do not need to have the same configuration. The main pump 11 is adapted to be rotated by the driving motor M _MP for the main pump, as the for the main pump drive motor M _MP, here DC brushless motor not shown is magnet coupling type use. The main pump drive motor M _MP and the booster pump drive motor M _BP are not limited in configuration / combination, and for example, one or both may be induction motors.

  Inside the pump casing (rotor casing) 50, two rotating shafts 51a and 51b are arranged in parallel, and the rotating shafts 51a and 51b are rotatably supported by bearings 53 and 53, respectively. A right-handed pump rotor 52a is fixed to the rotating shaft 51a, and a left-handed pump rotor 52b is fixed to the rotating shaft 51b. A fluid channel 56 is formed between the pump rotors 52 a and 52 b and the inner surface of the pump casing 50, and a suction port (intake port) 11 a is provided at the upstream end of the fluid channel 56. A discharge port (exhaust port) 11b is provided at the downstream end of the nozzle. The pump rotors 52a and 52b are in contact with each other while maintaining a slight clearance so that the gas sucked from the suction port 11a is transferred to the discharge port 11b. As the pump rotors 52a and 52b, a pair of pump rotors having an axial cross-sectional shape that contacts only on the pitch line may be used.

The rotary shafts 51a and 51b are made of, for example, SUS material, the pump rotors 52a and 52b are made of, for example, an aluminum alloy, and the pump rotors 52a and 52b are shrink-fitted to the rotary shafts 51a and 51b to form a pair of pump rotors. It is composed. The surfaces of the pump rotors 52a and 52b are subjected to nickel plating. Further, the pump rotors 52a and 52b may be formed on the outer periphery of the rotary shafts 51a and 51b with a resin material. Thereby, the pump rotors 52a and 52b can be manufactured at low cost. Rotary shaft 51a, the shaft end of 51b are connected to a rotary shaft of the drive motor M _MP for the main pump, so as to synchronize the inversion of the rotation shaft 51a, 51b by the magnet coupling.

  The suction port (intake port) 12a of the booster pump (BP) 12 of the vacuum pump system 10 having the above configuration is connected to the exhaust port of the reaction chamber of the semiconductor manufacturing equipment (not shown), and the booster pump (BP) 12 and the main pump (MP). 11 is operated, a product is formed in the booster pump (BP) 12 and the main pump (MP) 11, and foreign substances from the reaction chamber are flow paths of the booster pump (BP) 12 and the main pump (MP) 11. 56 may enter. If this product or foreign matter is caught between the pump rotors 52a and 52b, or between the pump rotor 52a or 52b and the pump casing 50, the pump rotors 52a and 52b are overloaded. Since these products and foreign substances are fragile, they can be discharged out of the crusher by rotating the pump rotors 52a and 52b with a strong rotational force.

Therefore, here, the inverter device INV _MP of the main pump power supply device 14 and the inverter device INV _BP of the booster pump power supply device 15 are the number of rated currents of the booster pump drive motor _MBP and the main pump drive motor _MMP. The inverter device has a capacity capable of supplying a current up to twice the upper limit. The main control device 30 monitors the current value supplied to the booster pump 12 and the main pump 11, for example, and monitors the load state of the booster pump (BP) 12 and the main pump (MP) 11 from the current value. .

For example, when it is determined from the monitoring of the load state that a product or a foreign object is caught in the booster pump 12, the main pump heater control device 23 and the booster pump heater control device 24 are controlled to increase the booster pump. The heater current (H _BP ) 21 and the main pump heater (H _MP ) 20 are cut off and the drive current (electric power) supplied to the main pump drive motor M _MP is restricted. The current (electric power) corresponding to the interruption and limitation can be supplied from the inverter device INV _BP of the booster pump power supply device 15 to the booster pump drive motor M _BP . At this time, the operating current of the main pump flow control valve 32 that sends the cooling water to the main pump (MP) 11 is also cut off, the flow control valve 32 is closed, and the supply of the cooling water to the main pump 11 is stopped.

Further, when it is determined that the product or foreign matter is caught in the main pump 11, the main pump heater control device 23 and the booster pump heater control device 24 are controlled to control the main pump heater (H _MP ) The heating current supplied to the heater 20 and booster pump heater (H _BP ) 21 is cut off, and the drive current (electric power) supplied to the booster pump drive motor M _BP is restricted, and this cutoff and restriction are performed. It is possible to supply the current (power) corresponding to the amount from the inverter device INV _MP of the main pump power supply device 14 to the main pump drive motor M _MP . At this time, the operating current of the booster pump flow control valve 33 that sends the cooling water to the booster pump 12 is also cut off, the flow control valve 33 is closed, and the supply of the cooling water to the booster pump 12 is stopped.

4 to 6 show a main pump drive motor M _MP , a main pump heater H _MP , a booster pump drive motor M _BP , and a booster pump heater when biting occurs in the booster pump (BP) 12. It is a figure which shows the power consumption change state of _HBP and the whole vacuum pump system. In the conventional vacuum pump system, as shown in FIG. 4, the pump operation is started at time t1, the main pump drive motor M _MP , the main pump heater H _MP , the booster pump drive motor M _BP , and the booster pump heating. The power consumption of the heater _HBP and the entire vacuum pump system changes as shown. When biting of the product or foreign object to the booster pump BP at point A occurs, the time that the power consumption of the drive motor M _BP for booster pump increases, the overall current consumption of the vacuum pump system exceeds a breaking current of the breaker 26 At t2, the breaker 26 is shut off, and the vacuum pump system operation is stopped.

In the vacuum pump system according to the present invention, as shown in FIG. 5, the pump operation is started at time t1, the main pump drive motor M _MP , the main pump heater H _MP , the booster pump drive motor M _BP , and the booster pump. The power consumption of the general heater _HBP and the vacuum pump system varies as shown in the figure. When biting of the product or foreign object to the booster pump BP at point A occurs, increased power consumption of the booster pump driving motor M _BP is, for the main pump heating at the time t2 exceeds a predetermined specified value of the point B heaters H blocks the heating current to the _MP and the booster pump heater H _BP stops heater. Thus the power consumption of the booster pump driving motor M _BP is raised by a strong rotation of the pump rotor between the point C ~D point, power consumption and product and foreign matter are crushed begins to decrease, E at time t3 which is a predetermined or less at the point, and resumes the power supply to the heater H _BP for heater H _MP and the booster pump for the main pump resumes heater. As a result, the current consumption of the entire vacuum pump system does not exceed the breaking current value of the breaker 26, and the operation is continued without stopping the vacuum pump system operation.

Further, in the vacuum pump system according to the present invention, as shown in FIG. 6, when the pump operation is started at time t1 and the product or foreign matter is caught in the booster pump BP at the point A, the booster pump drive motor M It increases the power consumption of the _BP, cut off the heating current to a main pump heater H _MP and heater H _BP for booster pump at the time t2 exceeds a predetermined specified value of the point B to stop the heater. Even this is not crushing products and foreign matter, if the power consumption of the drive motor M _BP for booster pump is not reduced, and reducing the power consumption of the drive motor M _MP for the main pump point C, further driving the booster pump The power consumption to the motor M _BP rises, and when the product and foreign matter are crushed by the powerful rotation of the pump rotor between the D point and the E point, the power consumption starts to decrease, and the F point becomes less than a predetermined value. at time t3 made, resume power supply to the heater H _BP for heater H _MP and the booster pump for the main pump resumes heater. As a result, the current consumption of the entire vacuum pump system does not exceed the breaking current value of the breaker 26, and the operation is continued without stopping the vacuum pump system operation.

As described above, when a product or foreign matter is caught in the booster pump (BP) 12 or the main pump (MP) 11, the booster pump heater (H _BP ) 21, the main pump heater (H _MP ) 20 and the main pump flow motor ( _MP ) 32 or the booster pump flow control valve ( _VBP ) 33, and the main pump drive motor _MMP or booster. Since the drive current supplied to the pump drive motor M _BP is limited and the cut-off and limited current can be supplied to the booster pump drive motor M _BP or the main pump drive motor M _MP , the vacuum pump Occurrence of product or foreign matter biting can be eliminated without changing the total amount of power used by the system 10.

In addition, as described above, products and foreign substances are fragile, so they can be generated in a short time by increasing the rotational force of the pump rotors 52a and 52b of the booster pump (BP) 12 and the main pump (MP) 11. Since the objects and foreign matters are crushed and discharged outside the machine, the main control device 30 determines that the booster pump (BP) 12 or the main pump (MP) 11 in which the biting has occurred returns to the normal state. A heating current is supplied to the pump heater (H _BP ) 21 and the main pump heater (H _MP ) 20 to flow the main pump flow control valve (V _MP ) 32 and the booster pump flow control valve (V _BP ). The operation current to 33 is returned to the original state, and the drive current to the booster pump drive motor _MBP or the main pump drive motor _MMP is returned to the original state.

FIG. 7 shows the inverter device INV _MP of the main pump power supply 14, the inverter device INV _{BP of} the booster pump power supply 15, the booster pump heater (H _BP ) 21, the main pump heater (H _MP ) 20, and the booster. The power capacity of the pump flow control valve (V _BP ) 33 and the main pump flow control valve (V _MP ) 32 and the conventional control, and the control according to the present invention causes the booster pump BP to bite and overload. It is a figure which shows the example of control in the case where it becomes, and the case where biting generate | occur | produces in the main pump and it becomes an overload. It is a figure which shows the comparative example of the vacuum pump system which concerns on this invention, and the conventional vacuum pump system.

As shown, power capacity 15KVA inverter device INV _MP of the main pump power supply device 14, and the power capacity of the power capacity 15KVA, for the main pump heater H _MP of the inverter INV _BP booster pump power supply unit 15 1. 5kVA, a power capacity 1.5kVA of the heater H _BP for booster pump, and the total power 33kVA vacuum pump system. In the conventional control, the inverter device INV _MP of the main pump power supply device 14, the inverter device INV _{BP of the} booster pump power supply device 15, the main pump heater H _MP , and the booster pump heater H _BP are always operated. Yes. Therefore, when the main pump 11 or the booster pump 12 is overloaded due to the biting of products or foreign matters, the number of rated currents is supplied to the motor for driving the overloaded pump in order to eliminate this overload. In order to flow a double current, the total amount of electric power must be increased by that amount, and the power supply system facility becomes larger.

On the other hand, in the control by the vacuum pump system according to the present invention, for example, when the booster pump (BP) 12 is overloaded due to biting, the main pump drive is driven from the inverter device INV _MP of the main pump power supply device 14. the power supplied to the motor M _MP limits from 15kVA to 10kVA, stops power supply 3.0kVA to heater H _MP and heater H _BP for booster pump for the main pump, minute electric power this limit and stop Since the amount 8 kVA is supplied from the inverter device INV _BP of the booster pump power supply 15 to the booster pump drive motor M _BP , overload due to biting can be eliminated without changing the total power amount 33 kVA.

Even when the main pump (MP) 11 is overloaded due to biting, the power supplied from the inverter device INV _BP of the booster pump power supply device 15 to the booster pump drive motor M _BP is limited to 15 kVA to 10 kVA. The power supply of 3.0 kVA to the heating heater H _MP for the main pump and the heating heater H _BP for the booster pump is stopped, and the electric power of 8 kVA corresponding to the restriction and the stop is supplied to the inverter device INV _{MP of the} main pump power supply device 14. from the supply to the drive motor M _MP for the main pump, without changing the total power 33KVA, you can eliminate overloading by biting.

In the vacuum pump system, a booster pump heater (H _BP ) 21 as a power consuming unit that consumes power in addition to the main pump drive motor M _MP and the booster pump drive motor M _BP , a main pump heater ( H _MP ) 20 and the main pump flow control valve 32 or the booster pump flow control valve 33, even if there is a power consumption unit other than this, if there is no problem in the operation of the vacuum pump system, the power supply to said power consuming unit stops, and supplies the correspondingly booster pump overloaded by biting power (BP) 12 or the main pump (MP) 11 of the driving motor M _BP or M _MP It is possible.

  In the vacuum pump system 10 described above, a vacuum pump system including two vacuum pumps, that is, a booster vacuum pump 12 and a main pump 11 as a plurality of vacuum pumps has been described as an example. However, the number of vacuum pumps is more than that. Also good.

  Furthermore, although the above embodiment has been described by taking the control when foreign matter is caught in the pump rotor as an example, the basic control is performed even in the overload operation state due to the rapid increase in the gas flow rate to the vacuum pump. The method is the same, and since power supplied to the pump motor is given priority, it is possible to cut off the power supply to the power consuming unit such as a heater.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Can be modified. Note that any shape or structure not directly described in the specification and drawings is within the technical scope of the present invention as long as the effects of the present invention are achieved. For example, an example in which a screw-type vacuum pump is used as a biaxial volumetric dry vacuum pump has been described. However, the technology of the present invention can be applied even if another type of volumetric transfer type biaxial vacuum pump such as a roots type is used. It is a range.

  The present invention cuts off or restricts power supplied to a power consuming unit other than an electric motor and / or within a plurality of dry vacuum pumps when any of the pump rotors in the plurality of dry vacuum pumps is overloaded. Limiting the power supplied to the motor that drives the dry vacuum pump that is not overloaded to the pump rotor, supplying power in preference to the motor that drives the dry vacuum pump overloaded to the pump rotor, Since the original power supply state is restored after the overload is eliminated, the pump rotor does not change the power capacity required for the entire vacuum pump system, including the inverter that supplies the motor that drives the dry vacuum pump, and the pump rotor is engaged with foreign matter. The maximum current up to several times the rated current can be supplied to the motor that drives the dry vacuum pump that is overloaded due to It can be used to empty the pump system.

10 Vacuum pump system 11 Main pump (MP)
12 Booster pump (BP)
14 Power source for main pump 15 Power source for booster pump 17 Electromagnetic switch for main pump 18 Electromagnetic switch for booster pump 20 Heater for main pump (H _MP )
21 Heater for booster pump (H _BP )
23 Heater controller for main pump 24 Heater controller for booster pump 26 Breaker 28 AC power (commercial power)
32 Flow control valve for main pump (V _MP )
33 Flow control valve for booster pump (V _BP )
35 Cooling water introduction pipe for main pump 36 Cooling water introduction pipe for booster pump 37 Drain pipe 41 Casing 50 Pump casing (rotor casing)
51a Rotating shaft 51b Rotating shaft 52a Pump rotor 52b Pump rotor 56 Fluid flow path

Claims (5)

A rotor casing is provided with a pair of pump rotors, each having a plurality of two-shaft displacement type dry vacuum pumps each having one rotating shaft, and at least one of the rotating shafts of each dry vacuum pump is rotationally driven by an electric motor. The driving power is supplied to the electric motor from the inverter device, and when the pump rotor is overloaded, the upper limit is set to several times the rated current of the electric motor from the inverter device to the electric motor. In a vacuum pump system equipped with a power consumption unit that consumes electric power in addition to the plurality of electric motors, which can supply a maximum current,
When any of the pump rotors in the plurality of dry vacuum pumps is overloaded, the power supplied to the power consuming unit other than the electric motor is cut off or limited, and / or in the plurality of dry vacuum pumps Limiting the power supplied to the motor that drives the dry vacuum pump in which the pump rotor is not overloaded, supplying power in preference to the motor that drives the dry vacuum pump that is overloaded in the pump rotor, A vacuum pump system comprising power control means for returning to the original power supply state after the overload is eliminated. The vacuum pump system according to claim 1,
The vacuum pump system, wherein the power consuming unit other than the electric motor is a heater provided individually for each of the dry vacuum pumps and individually controlling the temperature of the dry vacuum pump. The vacuum pump system according to claim 1 or 2,
The vacuum pump system according to claim 1, wherein the overload of the pump rotor is an overload caused by the pair of pump rotors or the pump rotor and the rotor casing being caught by foreign matter, or a rapid increase in gas flow rate. The vacuum pump system according to any one of claims 1 to 3,
The plurality of dry vacuum pumps are a main dry vacuum pump and a booster dry vacuum pump, and a suction port of the main dry vacuum pump is connected to a discharge port of the booster dry vacuum pump. A rotor casing is provided with a pair of pump rotors, each having a plurality of two-shaft displacement type dry vacuum pumps each having one rotating shaft, and at least one of the rotating shafts of each dry vacuum pump is rotationally driven by an electric motor. The driving power is supplied to the electric motor from the inverter device, and when the pump rotor is overloaded, the upper limit is set to several times the rated current of the electric motor from the inverter device to the electric motor. In the operation method of the vacuum pump system that can supply the maximum current, and further includes a power consumption unit that consumes power other than the plurality of electric motors,
When any of the pump rotors in the plurality of dry vacuum pumps is overloaded, the power supplied to the power consuming unit other than the electric motor is cut off or limited, and / or in the plurality of dry vacuum pumps Limiting the power supplied to the motor that drives the dry vacuum pump in which the pump rotor is not overloaded, supplying power in preference to the motor that drives the dry vacuum pump that is overloaded in the pump rotor, A method of operating a vacuum pump system, wherein after the overload is eliminated, the original power supply state is restored.

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